[APP-775] Add Welcome screen after account creation (#1038)

* add comments to step 1-3

* add onboarding screen

* add analytics for onboarding tracking

* fix useEffect

* change text

* change icon size

* put onboarding into bottom sheet modal instead of react navigation

* wip

* Simplify the type validation

* Fix: only trigger onboarding modal when account creation succeeds

* Add the 'session-ready' event which fires when the new session is stable

* Use the 'session-ready' event to trigger the onboarding modal

* update copy

* update copy

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Co-authored-by: Paul Frazee <pfrazee@gmail.com>

src/view/com/auth/create/Step3.tsx

@@ -10,6 +10,9 @@ import {createFullHandle} from 'lib/strings/handles'
 import {usePalette} from 'lib/hooks/usePalette'
 import {ErrorMessage} from 'view/com/util/error/ErrorMessage'
 
+/** STEP 3: Your user handle
+ * @field User handle
+ */
 export const Step3 = observer(({model}: {model: CreateAccountModel}) => {
   const pal = usePalette('default')
   return (